A Highly Efficient Coordination Polymer for Selective Trapping and Sensing of Perrhenate/Pertechnetate

A porous cationic Ag­(I) coordination polymer, [Ag­(1,2,4,5-p4b)]­(SbF₆) (TJNU-302) with the ligand 1,2,4,5-p4b (1,2,4,5-tetra­(pyridin-4-yl)­benzene), is reported that shows high sorption capacity (211 mg g^–1) and distribution coefficient K_d (5.8 × 10⁵ mL g^–1) as well as outstanding selectivity in 500 times excess of CO₃^2– or PO₄^3– anion for perrhenate removal. TJNU-302 can act as a crystalline turn-off sensor for perrhenate upon UV radiation. In this way, a test paper strip for sensing ReO₄^– could be produced. In water solution, TJNU-302 shows an efficient fluorescence quenching response to ReO₄^– ion, with the highest quenching percentage (86%) among all reported ReO₄^– sensors. These results could be elucidated by the bonding properties of single-crystal structures of TJNU-302 before and after perrhenate sorption, as well as density functional theory (DFT) calculations.